The Free Radical Group has shown that a number of novel compounds containing selenium atoms can act as efficient antioxidants, protecting the body against damage caused by a variety of oxidants produced during inflammation.
Dr David Pattison, joint Group Leader of the Free Radical Group with Professor Michael Davies explains,
“While it is common to describe oxidants and free radicals as ‘bad’ and antioxidants as ‘good’, this is somewhat of an oversimplification of a very complex scientific area, known as redox biology.”
This fascinating scientific field is concerned with the unique properties of oxidants, their ability to react with different targets and at different rates, and their varying potential to act in both beneficial and detrimental ways within the body.
In collaboration with the groups of Professor Carl Schiesser at the University of Melbourne, Professor Michael Davies in Denmark, and researchers in India, the Free Radical Group has conducted a series of studies looking at new selenium compounds as potential antioxidants. The results show that these compounds decrease the extent of oxidation of human plasma proteins at low concentrations, demonstrating their ability to act as potent oxidant scavengers.
Free radicals and other highly reactive oxidants are continually generated in the body as products of normal physiological processes and play an important role in maintaining normal cellular function. Excessive or misplaced production of these oxidants, however, can result in tissue damage that has been implicated in the development of many inflammatory diseases, including atherosclerosis.
As an example, the enzyme myeloperoxidase (MPO) is released by white blood cells during inflammation, and reacts in the body to generate a range of oxidants including hypochlorous acid (HOCl, a major component of household bleach), which are bactericidal and an important part of the immune response. There is strong evidence however that overproduction of HOCl contributes to the development of atherosclerosis.
In exciting new work Luke Carroll, a PhD student in the Inflammation Group at the HRI, has shown a dose-dependent decrease in the concentration of various oxidants upon addition of these new selenium compounds. These studies demonstrate that these compounds react rapidly with MPO-derived oxidants that are relevant to inflammatory diseases, particularly atherosclerosis, where markers of HOCl-induced damage are present.
This important work continues, with the ability of these new selenium compounds to react with other oxidants that are relevant to the development of atherosclerosis currently being investigated.
"There is still a lot of work to be done in investigating the reactions of these novel selenium-containing compounds, but we hope that in the future these compounds will undergo extensive clinical trials, and maybe one day will be available as a potential treatment for atherosclerosis, cardiovascular disease and related inflammatory disorders,” Dr David Pattison says.